DIVERSITY OF PLANT SPECIES ALONG WITH INVASIVE ALIEN SPECIES OF SHOREA ROBUSTA GAERTN AND PINUS ROXBURGHII SARG (350-1900 M) FORESTS OF NAINITAL DISTRICT WEST HIMALAYA

Biological invasions are often thought to be one of the leading threats to global biodiversity. Plant invaders of natural ecosystems, also termed ‘environmental weeds’, have been shown to inhibit the recruitment of resident native species by preventing seedling establishment and growth, and modifying plant pollinator interactions displace resident species through direct below and above ground competition for resources, such as space , water, nutrients, and light and modify or ‘engineer’ ecosystem processes and the physical resources of the recipient community, such sedimentation, nutrient cycling and disturbance regimes. In the present study the list and documentation of total associated plants species were prepared and total 247 species were found which includes 39 tree species, 65 species of shrub, 132 species of herb (grasses and climber). All these species belongs to 75 families and under 176 generas. Among all the families the most dominated family were Poaceae 27 species followed by Fabaceae 26 species, followed by Asteraceae 21 species, Lamiaceae 18 species and Malvaceae 10 species were recorded.